Cornyebacterium and Rhodococcus

Question 1

What shape is Corynebacterium?

Answer 1

club shaped

Question 2

How does Corynebacterium appear on gram stain?

Answer 2

gram positive rods

Question 3

What are palisades?

Answer 3

the tendency for bacteria to form in clumps or parallel groups

Question 4

What size colonies does Corynebacterium have?

Answer 4

small to medium, non-hemolytic colonies

Question 5

What bacteria does Corynebacterium share cell wall antigens with?

Answer 5

Mycobacterium, Rhodococcus, and Nocardia

Question 6

What dpes the human pathogen of Corynebacterium diptheriae cause?

Answer 6

diptheria

Question 7

What countries still have a diptheria problem?

Answer 7

under developed countries

Question 8

What clinical signs are associated with diptheria?

Answer 8

conjunctivits, bull neck, severe myocarditis

Question 9

What does Corynebacterium renale cause in cattle?

Answer 9

pyelonephritis

Question 10

What does Corynebacterium renale cause in sheep and goats?

Answer 10

posthitis

Question 11

What is the morphology of Corynebacterium renale?

Answer 11

short, stumpy rods which may be thicker on one end - non hemolytic

Question 12

What does Corynebacterium renale grow well on?

Answer 12

BAP and sterile urine

Question 13

Is Corynebacterium renale catalase positive or negative?

Answer 13

positve

Question 14

What test is pretty indicitive that Corynebacterium renale is the pathogen in question?

Answer 14

urease - rapid urease result

Question 15

What is the natural habitat of Corynebacterium renale?

Answer 15

urethra and prepuce of normal cattle, sheep, and goats

Question 16

What type of infection is Corynebacteria renale?

Answer 16

ascneding usually in periparturient cows

Question 17

Is immunity from Corynebacteria renale possible?

Answer 17

nope

Question 18

What is used to treat Corynebacteria renale?

Answer 18

penicillin

Question 19

What specific urinary lesion does Corynebacteria renale cause?

Answer 19

pizzle rot - ulcerative posthitis

Question 20

What causes pizzle rot?

Answer 20

excessive protein in the diet leads to increased quantities of urea in the urine. C. renale breaks down the urea and converts it into ammonia which is very irritating to the skin and mucosa around and in the prepuse

Question 21

How do you treat pizzle rot?

Answer 21

topical ointments or surgical intervention

Question 22

What are the two biovars of Corynebacterium pseudotuberculosis?

Answer 22

biovar ovis and biovar equi

Question 23

How does biovar ovis react with nitrate, what does it cause, and in what species?

Answer 23

it is nitrate negative and causes caseous lymphadenitis in sheep and goats

Question 24

How does biovar equi react with nitrate, what does it cause, and in what species?

Answer 24

it is nitrate positive and causes abscesses in horses

Question 25

Which biovar of Corynebacterium pseudotuberculosis infects cattle?

Answer 25

both of them

Question 26

How does Corynebacterium pseudotuberculosis appear on gram stain?

Answer 26

gram positive pleomorphic short rod that can be mistaken for cocci

Question 27

What do the colonies of Corynebacterium pseudotuberculosis look like?

Answer 27

small grayish to yellow and sometimes pinkish colonies which can fragment easily - hemolytic pattern varies

Question 28

What definitive tests are used to identify Corynebacterium pseudotuberculosis?

Answer 28

urease and CAMP

Question 29

How does Corynebacterium pseudotuberculosis react on CAMP?

Answer 29

it has a reverse CAMP reaction and inhibits staphylococcal beta hemolysin

Question 30

What toxins does Corynebacterium pseudotuberculosis have?

Answer 30

phospholipase D and surface lipid

Question 31

What is the basis for the vaccine for Corynebacterium pseudotuberculosis?

Answer 31

phospholipase D

Question 32

What is the surface lipid of Corynebacterium pseudotuberculosis toxic to?

Answer 32

phagocytes

Question 33

Where is Corynebacterium pseudotuberculosis present?

Answer 33

in soil, in abscesses, and on skin

Question 34

How is Corynebacterium pseudotuberculosis spread?

Answer 34

when an abscess ruptures the organism contaminates feeders, waterers, etc.

Question 35

How does Corynebacterium pseudotuberculosis infect?

Answer 35

through wounds, abrasions, insect bits, shearing wounds, and it can be inhaled

Question 36

Where does Corynebacterium pseudotuberculosis travel after entering a host?

Answer 36

it travels to draining lymph nodes

Question 37

What type of parasite is Corynebacterium pseudotuberculosis?

Answer 37

facultative intracellular parasite

Question 38

What type of lesions does Corynebacterium pseudotuberculosis cause?

Answer 38

onion-skin lesions

Question 39

What species does Corynebacterium pseudotuberculosis commonly infect?

Answer 39

sheep and goats

Question 40

What region is biovar equi seen in?

Answer 40

The west - specifically California and Colorado

Question 41

What lesion does biovar equi cause (specific disease)?

Answer 41

pigeon fever or Dryland distemper

Question 42

Aside from goats, sheep, and horses, what species does Corynebacterium pseudotuberculosisinfect?

Answer 42

cattle, bison, camels, and humans

Question 43

How is Corynebacterium pseudotuberculosis diagnosed?

Answer 43

based on clinical signs or the synergistic hemolysis inhibition test

Question 44

What aids in preventing against Corynebacterium pseudotuberculosis infection?

Answer 44

antigen against the phospholipase - once abscesses form the antibody is not helpful

Question 45

How can C. pseudotuberculosis be prevented?

Answer 45

quarantine, drain abscesses, and immunization

Question 46

How can C. pseudotuberculosis be treated?

Answer 46

drain the abscesses or injecting them with Draxxin

Question 47

What is the morphology of Rhodococcus equi?

Answer 47

large rod (in liquid media) with pleomorphism ranging into cocci (on plate media)

Question 48

What do the colonies of Rhodococcus equi look like?

Answer 48

non hemolytic small to large, distinct, moist, mucoid, and flowing

Question 49

How does Rhodococcus equi react in carbohydrates?

Answer 49

it doesn't ferment

Question 50

What other test helps to identify Rhodococcus equi?

Answer 50

CAMP - strong reaction

Question 51

What antigens are specific to Rhodococcus equi?

Answer 51

virulence-associated protein A and mycolic-type acids

Question 52

What is the natural habitat of Rhodococcus equi?

Answer 52

intestinal tract of horses especially in young foals and grows in soil

Question 53

What is Rhodococcus equi resistant to?

Answer 53

pretty much everything - it is very hardy

Question 54

What diseases does Rhodococcus equi cause?

Answer 54

suppurative bronchopneumonia, enteritis, internal abscesses, and joint infections

Question 55

Aside from equine, what does Rhodococcus equi infect?

Answer 55

swine and humans

Question 56

In swine. what is Rhodococcus equi maybe secondary to?

Answer 56

tuberculosis

Question 57

What is immunity to Rhodococcus equi dependent on?

Answer 57

age - presence of macrophages

Question 58

Is there a vaccine for Rhodococcus equi?

Answer 58

no

Question 59

How do you treat a Rhodococcus equi?

Answer 59

long-acting macrolides and rifampin